Backyard Aquaponics
A place to discuss aquaponics

This past summer my well was down for over a month. I had to haul water, so reduced irrigating the garden to a minimum. We normally used water from our 1000 gal fish tank daily for irrigation, and make up fresh. We do so because the grow bed is to small due to available space nearby. We lost almost all of the fish in that tank before the well was restored.

Solution: erect more grow beds even if they are twenty feet to 40 feet away. I salvaged three old boat floats 32"x96", fiberglass with styrofoam fill. After cutting the tops off and removing the foam, I positioned them on drums. The drums give a slight fall back to the tank, but the slope means three different grow bed levels. That meant three different water supplies and retrurns.

Solution: Rainbird timer and control valves, cheap and readily available. I used my spare nr. 5 mag pump to feed the 3/4" sprinkler valves, with a strainer at the tank. The timer allows up to four cycles a day for each valve, up to 4 hours apart. By varying the supply time and squeezing off the return I can have four flood and drain cycles for each grow bed, daily. The problem is that the rainbird is designed for 50 psi or so and the flow was to low.

Solution: Rainbirds are diahram pilot operated valves. As Kadaput sugested in 2007 they can be opened, the diahram spring shortened and the pilot hole drilled out. The result is double the flow and suitable supply using my small 50 watt pump. The Mag pump will not mind pumping against closed valves. I run a seperate pump for oxygenation with an irrigation option. I put in a small 150 gal FT with koi to supply the original GB which is full of comfry for fodder.

to update anyone inerested: The sprinkler valves are working fine. I run each bed for 55 min each time six times a day, four hour intervals. The timer I use has six stations and I use two stations for each valve by simply tieing the station leads togeather, going to the valve. So far the plants are doing fine. I do not have many fish in the tank yet but believe that this will serve a fairly dense fish load once the bacteria are established. I keep a second pump as a fountain for oxygen.

Do you have a link back to the thread with the instructions on exactly how to modify the valves?

Anyone into electronics could probably knock together their own controller that would make sure there is always one valve open instead of only being able to have 4 cycles per day per station. Could probably be done with a 8 pin picaxe chip and relays along with a hand full of other components.

Might I suggest that instead of leaving the pump on while all valves are closed, perhaps you put a T and a Riser. Figure out how high the water gets in that riser when only one valve is open, cut the riser a couple inches above that and insert another T sick an extra length of pipe above the T then send the water over and down to the fish tank out the side of the T so that when there is a valve open, the water will go to the grow bed but when all valves are closed, you will get water going back to the fish tank. This might also give warning when a valve clogs up since you would get water going back to the fish tank when it should be going to a bed.

Mor'n TClynx
Rather than try to find the BYA page I will tell you how I modified the valves. first unscrew the solinoid coil to get it out of the way, then remove the top of the vlave. the diaphram with spring come off and there are two tiny holes in the body. One goes to the solinoid and the other comes from the supply. I drilled those holes out to 1/8 inch and snipped the top two turns off the spring. That will more than double the flow from a nr. five mag pond pump. There is a u-tube about modifieng these valves for paint ball use.
The six station rainbird is cheap and works fine. I do have the pump runing with all the valves closed for 3.5 hrs. a day so may try your riser idea, but it has caused no problem so far. I do have a fine strainer on the pump outlet that I clean daily.

Sorry that last is an error. The holes are in the top portion of the valve. Drilling out to 1/8 in. makes a constant leaker. It wont shut off. So use a 3/32 drill to get more flow and a better seal. This works in both the 3/4 and 1" vlaves, but have not tried it on the socalled low flow valves...which are still designed for 50 psi or more.
TCLynx: I intend to run some verticle gardens over the pond so need a second pump for that anyway. So will not bother with the riser to return flow to the tank between flood cycles.

Ah, I just hate to choke back pumps like that, hence my recommendation for the riser.

And I probably won't bother with something that requires a screen be cleaned daily because I like the ease of letting the gunk go to the grow beds.

But I might have to go searching for the U tube and test it out anyway someday.